1. Field of the Invention
The present invention is directed to a safety belt for vehicle occupants. The invention further concerns a safety belt with roller member arranged therewith to provide a force limitation member.
2. Description of the Prior Art
Automatic rollers intended to permit the extraction of the safety belt from the device when the vehicle passenger moves slowly are known. If the movement of the passenger takes place suddenly, a locking mechanism prevents extraction of the safety belt. The safety belt can likewise be locked when a deceleration exceeding a definite value occurs on the vehicle and roller.
The roller, which facilitates placing the safety belt in place, thus guarantees freedom of movement of the user.
If the vehicle suddenly encounters an obstacle, the safety belt prevents the user from being thrown forward and secures him in his seat. When the deceleration of the vehicle is relatively high, the force exerted on the body strapped by the safety belt can become excessive and cause bodily injury. This force is somewhat reduced as the result of elastic stretching of the safety belt which absorbs the energy.
Roller arrangements are already known which are associated with a force limitation member in the same assembly. The force limiter permits in general, restraining or locking the belt roller axle up to a predetermined loading. However, since the load supportable by the passengers of a vehicle is variable because such depends notably on their weight and constitution, it has been proposed to make the threshold of functioning of the limitation member adjustable. The successive improvements of the rollers have thus lead to relatively complex arrangements.